Although they are commonly referred to as
"koala bears" because of the resemblance to
teddy bears, koalas are not bears. The koalas are
marsupials. This is one of the oldest classes of animals,
existing since over fifty thousand years ago.
Koalas average about twenty-six pounds in weight
and thirty-one inches in length. The coat of the koala
is the thickest among the marsupials and has a
gray to tawny color. White coloration appears on
the chin, chest, and forelimbs. The fur is short,
soft, densely packed, and springy to the touch. It is
the most effective fur insulation among animals.
The koalas do not rely on fat beneath the skin for
insulation; rather, blood flow to the extremities
can be reduced as a means to conserve heat. In the
rain, water runs off the koala's fur. Only sick koalas
will appear to be wet when it rains.

Koala Life
Koalas are nocturnal and highly arboreal, living
solitary lives high up in eucalyptus trees. Koalas
are known as phalangers, because they use their
hands and hind feet to effectively grip tree trunks
and branches when tree climbing and jumping
from tree to tree. They walk with a clumsy gait in
the following sequence: front right foot then back
left foot, front left foot, back right foot. They have a
very specialized diet, feeding almost exclusively
on the leaves of a few species of eucalyptus. The
leaves provide most of their water intake; in fact,
the word "koala" means "no drink" in Aboriginal
languages. For an average day, a koala will consume
about a pound of leaves. They are very fussy
eaters, typically being very careful
in selecting which leaves from a
bough to ingest. The koala uses a set
of thirty teeth, comprising incisors,
canines, premolars, and molars, to
chew the eucalyptus leaves. Each
day the koala spends approximately
eighteen to twenty-one hours sleeping
or resting.
In order to communicate, the koala
uses a range of vocalizations.
The male koala uses a deep, grunting
bellow to communicate its physical
and social position. The sound
can resemble a far-off rumbling, like
a motorcycle or pig snorting. During
the mating season, the koala
will use the bellowing as a means to
locate and accurately pinpoint potential
mates. The mating call is a
deep, loud, guttural sound that can
be heard for long distances. Female
koalas do not show the same level
of bellowing. Their calls communicate
aggression and are part of the
mating ritual. Both the male and
female koalas share a similar call,
sounding like a baby screaming.
This is often accompanied by shaking
and signals fear. Mother and
cubs make soft squeaking noises to
one another, as well as humming or
murmuring.

Koala Reproduction
Females of the species have a pouch in which the
young develop. The young are born in nearly embryonic
form about the size of a human's little finger.
After birth, the infant travels to the mother's
pouch, where it attaches to teat. The teat then becomes
engorged and forms a seal with the newborn.
A single offspring is usually born. It is not
until twenty-four weeks after birth that the young
is covered with fur and develops teeth. The first
six months of life are spent in the mother's pouch.
The cub remains with the mother until about
twelve months after birth. Mating is a brief event
that takes place about once a year. Male koalas are
nomadic and play virtually no part in the raising
of the young. Extensive chlamydia infection has
caused widespread infertility in female koalas
and is a major contributing factor in their declining
numbers.

Koala Facts

Classification:
Kingdom: Animal
Phylum: Vertibrata
Class: Mammalia
Subclass: Marsupialia
Order: Diprotodontia
Suborder: Vombatiformes
Infraorder: Phascolarctomorphia
Family: Phascolarctidae
Genus and species: Phascolarctos cinereus
Subspecies: P. c. victor (Victoria), P. c. cinereus (New South Wales),
P. c. adustus (Queensland)
Geographical location: Two main groups living out in the wild
are in eastern Australia in an area extending from Cooktown
in northern Queensland to southwestern Victoria; have been
introduced into western and southern Australia
Habitat:Wild eucalyptus forests and woodlands; they are found
only in pockets with suitable vegetation of a relatively small
number of eucalyptus species that they prefer to ingest
Gestational period: Thirty-five days
Life span: Thirteen to eighteen years
Special anatomy: Females have a pouch that faces the rear and
has a drawstring type muscle which can be tightened to close
the opening; mammary glands are located along the abdomen
within the pouch; females have a duplicate reproductive system
with two vaginas; males have dual-pronged, forked penises;
each hand has two opposable thumbs, which are crucial
for the ability to climb and cling to trees; digestive system includes
a caecum, a structure used to digest eucalyptus leaves
and assist in water extraction